This project, a collaborative effort by the NCI, EPA and other federal agencies, was initiated to provide more data relative to skin cancer and harmful solar ultraviolet. An urgent need for these data has existed since recent scientific reports have warned about the decomposition of stratospheric ozone by nitrogen oxides and chlorofluoromethanes (CFM's). Federal regulatory agencies have already recommended bans on the use of aerosl spray cans which use CFM's as propellants. In the near future, there will be critical reviews of all pertinent information by government as well as individual interests concerned with the threat of increased human skin cancer due to excess amounts of UV-B reaching the earth's surface, as its protective ozone shield is depleted. As mandated by Public Law 95-95 (amendment to the Clear Air Act of 1977), the NCI is continuing its investigations in this area. This will provide more reliable national estimates of the degree of morbidity from nomelanoma skin cancer as well as epidemiologic data on host and environmental factors other than solar ultraviolet, associated with increased risk. New leads from 10 surveys just being completed will be investigated.